In the process of shipping an article from one location to another, a protective packaging material is typically placed in the shipping case, or box, to fill any voids, to block, to brace and/or to cushion the article. Various types of packing products have been used to pack articles in shipping containers, including a crumpled paper dunnage product. Paper is a biodegradable and recyclable material composed of a renewable resource, making it an environmentally responsible raw material.
Various types of conversion machines heretofore have been used to convert sheet stock material into a dunnage product. The conversion of sheet material into a crumpled dunnage product may be accomplished by a cushioning conversion machine, such as those disclosed in U.S. Pat. Nos. 4,750,896; 4,884,999; and/or 5,607,383. (These patents are assigned to the assignee of the present application and their entire disclosures hereby are incorporated herein by reference.) Each of the cushioning conversion machines disclosed in the above-identified patents includes a conversion assembly which converts sheet stock material composed of one or more plies into a relatively less dense three-dimensional cushioning product. The conversion assembly includes a forming assembly which forms the sheet stock material into a strip of cushioning that is severed to form discrete pads useful as a packing material.
Prior art cushioning products have included a pair of pillow portions formed by inwardly turned lateral edge portions of one or more of the layers of stock paper. The central region of this structure is compressed and connected to form a central compressed portion between the pillow portions.
Although the cushioning conversion machines disclosed in the above-identified patents adequately perform their connecting and other functions, they generally are limited in the speed with which the cushioning product can be produced. In addition, although cushioning products produced by cushioning conversion machines can be used as void-fill dunnage, the process of forming a cushioning product from sheet stock material generally results in a yield lower than what might otherwise be needed for use as a void-fill. The lower yield is caused in part by crimp loss, i.e., a loss of longitudinal length of the resulting cushioning product relative to the length of the starting sheet stock material. In a void-fill dunnage product, which usually does not need substantial cushioning properties, it would be desirable to reduce longitudinal crumpling to minimize crimp loss and increase the length of the produced dunnage relative to the length of the starting sheet stock material, while also greatly increasing the speed at which a given length of dunnage is produced.